1. Field
Example embodiments relate to optical filters, color filters using optical filters, and display apparatuses using color filters.
2. Description of the Related Art
Color filters are conventionally manufactured using a pigment dispersion method in which a solution containing a dispersed pigment is coated on a photoresist and the photoresist is patterned. Because the pigment dispersion method uses a photolithography method, a relatively large-sized screen may be realized not only with thermal and chemical stabilities but also with color uniformity. However, because the color characteristics of such pigment-type color filters are determined by unique absorption spectrums of the dispersed pigment and the light transmissivity is decreased as the thickness of the pigment-type color filters is increased, luminance is decreased in regard to higher color purity color filters.
There has been recent interest in photonic crystal color filters based on structural colors. The photonic crystal color filters use nanostructures which are smaller than the wavelengths of light to control the reflection or absorption of light incident from the outside, to thereby reflect (or transmit) light of desired colors and transmit (or reflect) light of undesired colors. The photonic crystal color filters have a structure in which nano-sized unit blocks are periodically arranged at predetermined intervals. The optical characteristics of the photonic crystal color filters are determined by the size and periods of the nanostructures, and thus the photonic crystal color filters having improved wavelength selectivity and a color bandwidth that may be adjusted with relative ease may be manufactured by manufacturing predetermined nanostructures that are appropriate for a predetermined wavelength.